This invention relates to a core assembly for coil units which charges an electric car and to a method for producing the same.
In general, a magnetic coupling device includes a core assembly which constitutes a magnetic circuit for magnetically coupling a primary coil in a primary coil unit connected to an external power source device to a secondary coil in a secondary coil unit connected to a battery in the electric car. When both units are interconnected and the primary coil is energized, an induction electromotive force is generated in the secondary coil by a generated magnetic flux to charge the battery.
In such a magnetic coupling device, it is impossible to prevent a core of the core assembly from generating a heat due to a hysteresis loss of a magnetic material and the like. Consequently, there was a problem in which the magnetic coupling device as a whole is brought into a raise in temperature by a heat source of the core upon charging the battery.